In general a car hoist is specifically adapted to lift cars by their frames or to lift them by their wheels. In one form of car hoist the actual lifting is carried out by a centrally disposed ram actuated by fluid pressure. It will be appreciated that where a car is lifted by its wheels, maintenance work on the wheels or suspension is difficultly performed. Conversely, where a car is hoisted by the frame, access to the underbody of the car is usually unduly restricted. It has been heretofore proposed to utilize with the ram both a runway for lifting the car by its wheels and a spider for lifting the car by its frame. In certain of the proposals the decision of whether to employ the runway or spider must be made prior to actuating the ram to hoist the car, so as to interlink the runway and spider suitably. In other proposals the car may be hoisted in one mode; a propping system is then employed to relieve the weight from the ram whilst the spider and runway are inter-converted or unlinked.
Whilst in certain of these other proposals the systems are mechanically quite simple, their installation may be more complex than that of the conventional certral cylinder hydraulic type of car hoist which is currently employed in the automotive service industry.